Re: PyCXX question on __module__ attribute

[Barry S. <ba...@ba...>]

> On 28 Apr 2016, at 10:12, kishor sharma <kis...@gm...> wrote:
> 
> >Its been a long time since I used pickle. Personally I would avoid pickle because of the security and robustness issues.
> 
> Anyway. It looks like if you want to pickle an extension object you have to implement the
> __reduce__ and/or __reduce_ex__ methods. You would have to see what pickle does with the tuple returned by __reduce__ to recreate the objects. You can also register functions to assist pickle.
> 
> Given that the reason a C++ extension module is created is to wrap around complex resources I wonder if
> its reasonable to attempt to pickle a C++ object.
> 
> 
> Thanks Barry.  If we leave pickling issue for a while, do you know why __module__ is not when we create the extension using PyCXX though we pass the module name using below
> 
>     example_module()
>         : Py::ExtensionModule<example_module>( "example" )
>  
> Most of the python extension module have __module__ set which PyCXX extension doesn't.
> 
> In [4]: cPickle.load.__module__
> Out[4]: 'cPickle'
> 
> 
> Any thoughts?

The module interface has changed a lot over time. No one noticed the need to have __module__ on the extension module.

It is clearly not that important to python or we would have seen problems before now.

If  seem to be a low priority to fix if only pickle is affected and pickle is not useful to use with C++ extensions.

You might like to add a bug report to tack this issue. If you have a patch to add __module__ I’ll review and add.

Barry


> 
> Thanks,
> Kishor
> ------------------------------------------------------------------------------
> Find and fix application performance issues faster with Applications Manager
> Applications Manager provides deep performance insights into multiple tiers of
> your business applications. It resolves application problems quickly and
> reduces your MTTR. Get your free trial!
> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z_______________________________________________
> CXX-Users mailing list
> CXX...@li...
> https://lists.sourceforge.net/lists/listinfo/cxx-users